On testwiki while navigating to https://test.wikipedia.org/wiki/Special:CentralNoticeBanners/edit/Seddon_Sandbox
I was trying to figure out how to undelete / restore the banner.
```
[WlcpDgpAAD8AAGtGeZYAAACN] /wiki/Special:CentralNoticeBanners/edit/Seddon_Sandbox BannerExistenceException from line 351 of /srv/mediawiki/php-1.31.0-wmf.16/extensions/CentralNotice/includes/Banner.php: No banner exists where tmp_name = Seddon_Sandbox. Could not load.
Backtrace:
#0 /srv/mediawiki/php-1.31.0-wmf.16/extensions/CentralNotice/includes/Banner.php(177): Banner->populateBasicData()
#1 /srv/mediawiki/php-1.31.0-wmf.16/extensions/CentralNotice/includes/Banner.php(699): Banner->getName()
#2 /srv/mediawiki/php-1.31.0-wmf.16/extensions/CentralNotice/includes/Banner.php(704): Banner->getDbKey()
#3 /srv/mediawiki/php-1.31.0-wmf.16/extensions/CentralNotice/special/SpecialCentralNoticeBanners.php(388): Banner->getTitle()
#4 /srv/mediawiki/php-1.31.0-wmf.16/extensions/CentralNotice/special/SpecialCentralNoticeBanners.php(420): SpecialCentralNoticeBanners->getBannerPreviewEditLinks()
#5 /srv/mediawiki/php-1.31.0-wmf.16/extensions/CentralNotice/special/SpecialCentralNoticeBanners.php(85): SpecialCentralNoticeBanners->showBannerEditor()
#6 /srv/mediawiki/php-1.31.0-wmf.16/includes/specialpage/SpecialPage.php(522): SpecialCentralNoticeBanners->execute(string)
#7 /srv/mediawiki/php-1.31.0-wmf.16/includes/specialpage/SpecialPageFactory.php(578): SpecialPage->run(string)
#8 /srv/mediawiki/php-1.31.0-wmf.16/includes/MediaWiki.php(288): SpecialPageFactory::executePath(Title, RequestContext)
#9 /srv/mediawiki/php-1.31.0-wmf.16/includes/MediaWiki.php(854): MediaWiki->performRequest()
#10 /srv/mediawiki/php-1.31.0-wmf.16/includes/MediaWiki.php(524): MediaWiki->main()
#11 /srv/mediawiki/php-1.31.0-wmf.16/index.php(42): MediaWiki->run()
#12 /srv/mediawiki/w/index.php(3): include(string)
#13 {main}
```
This should probably be a nicer user facing error, or simple message saying the page doesn't exist.